Drill pipe protector



May 2, 1933. w. G. SMITH DRILL PIPE PROTECTOR Filed Jan. 25, 1930 WP/farli? BY y Patented May 2,

WALTER G; n SMITH, or' rosfaiiennns, cnnironivin i nRILLrirn rnorncron 1 l i Application sied January 25,`1930.` sriainaeaaeve.

`My invention relates to drill pipe protectors ,for preventing i or minimizing engagel `ment `of astring of drill pipel with the nte- A ft;

rior` of .a well casing orwellinwhich the string of ,drill `pipe is being operated.`

My invention has itsprincipal use; in the rotary systemof'well` drilling, in which a well is bored by the use of a drill bit secured "to the `lowerfend of a stringvofwdrill pipe rotated by a power device situated ad jacent to the upperendof the well. Owing 'to the characteristic conditions encounteredy in rotary well drilling, among-which is the bending of the string ofdrill pipe due to the superposed` weightthereof, it is `impossible to rotate the string of'drill pipe in centralized" position within thefwellcasing or bore of t the well, this resultingfin the drill pipefric- Les tionally engaginglthe well casingor the open Pill bore of` thewell` so as to cause a very rapid wearing away of the drillpipe couplings and toolf joints. The engagement `of the drill pipefwith theinterior of a casing often results in wearing a hole `in thecasing, which allowswater to Venter the interior ofthe well. rllhese holes `are very diiiicultto locate, and

i great care must be exercised Vin cementingoff the adjacent earthy structure so as to stop leakage into the interior of the well.

My invention comprehends a device which may be placed on a drill pipe structurehaving a resilient cylindrical Vwearing surface of larger diameterthan the couplings and tool joints employed inthe drill pipe strucf ture so. as to prevent. engagement ofthe `metal parts of the drill pipe Vstructure with the well casing and also with the Wallof an opened well bore. Theresilient material ein-v ployed is preferably a rubber composition having wear resisting characteristics and beingespecially `adapted'for lubrication by wawearing away of the drill ter or drilling mud. By use of this device', pipe structure and well casing is minimized.

It is an object of my invention to provide `a cylindrical body of resilient, `wear resisting material adapted to be secured on the'drill j pipestructure as a result'ofV the contractile characteristics of the cylindrical body. It isan' obj ectgof myinvention to provide a cylindrical body of rubber-compound with circular resilient reinforcing members therein which will supplement the natural resilience of'tlie rubber body and will therefore cause the drill pipe :protector to adhere se# curely to the drill pipe on whichV it is mount-.1 i

ed. i It is knownt-hat at the present time drill pipe protectors are employed in the form'of a cylindrical body of resilient rubber. In order to procure a. practical def grec of resiliencein the cylindrical body,` eX-` pensive materials inust be selected, and often bestfrictional characteristics of thelrubber compound must befsacrificed in order to "at tainthe desired degree of'resilience, for if the cylindrical ,body has not suliicient resil-A L ieiice-and strength; it will not reinainin operative position on the drill pipe but will be moved over couplings and Stool joints by engagement with the surface of the casing or the wall of a well when the drill pipe structure is being raised, lowered, or operated. My present invention, as the result vof the use of strong and very resilient springs therein, grips the drill pipexsecurely and permanently,` sog-that it iscausedgto remain inthe position of operation in which it originally; placed on the drill pipe. The structure isof such strength `that in use `of the drill pipe my drill pipe protector will not be!` moved over couplings and tool joints.

An object ofthe inventionisto provide a drill pipe protectorconsisting `of a cyli1idri` cal bodyV ofrubber .materia-l, selected prin- Vcipally for its wear resisting and non-fries" tional characteristics, having therein resilient spring-members to yprevideample resilience 1 for causing the 'protector to grip the:` l

drill pipesecurely. l t

An advantage of my invention isthat a rubber compound may be selected for its `frictional and wear resisting characteristics and the lack of resiliencethereof may be `more than compensated for by a circular reinforce-` Y ment of strong spring members. j

Further objects and advantagesof the invention will be lmade evident throughout the following part of the specification.

Referring to thedrawingwhich isfor il? lustrative purpOSeS 01115", L

Fig. 1 is a partly sectioned elevation showing my invention in use on a drill pipe Within a Well casing.

Fig. 2 is an enlarged, vertical diametral cross section through my new drill pipe protector and a portion of drill pipe on which it is mounted.

Fig. 3 is a horizontal cross section substantially on a plane represented by the line 3-3 of Fig. 2. In this sectional vie-W a spring reinforcing element of the drill pipe protector is shown in elevation.

Fig. l is a fragmentary detail View showing a reinforcing spring which maybe employed in the practice of the invention.

Fig. 5 shows a flat type ofireinforcing spring which may be employed in the practice of the invention.

In the utility view, Fig. 1, I show a drill pipe structurel() consisting of lengths or joints of pipe 11 secured together by couplings and by tool joints 12. In .the drilling of a Well 13, the drill pipe 10 is extended Within the Well and through a casing 14 set therein. To prevent engagement of the drill pipe structure 10-and its couplings and tool joints 12 With the Well casing or Wall of the. Well, my'drill pipe protector' 15 is mounted on the drill pipe structure 1() in substantially the manner shown, it being' preferable to place the protector 15 ladjacent to a coupling or tool joint '12 and surrounding or mounted upon a length of pipe 11 adjacent to such coupling or tool joint 12. As shown in Figs.

f 2 and 3, the drill pipe protector 15 consi-.sts

of a cylindrical body 16 of resilient, Wear resisting material, preferably having an internal diameter Il) smaller than the ext-ernal diameter of the drill pipe 10 on which it is to be mounted and having an external diameter OD Which is greater than the external diameter of the tool joint 12 and suchfollowing manner. An inner annular Wall or tube 21 of relatively raw, or vulcanizable, rubber compound of the desired length is first formed, this Wall having a diameter D and being of a thickness equalto approximately ag of an inch. Springs 2O having a central core 22 of vulcanizable rubber' extending therethrough are then Wound upon the inner Wall 21, it being preferable to exert a pull on the springs 20 so as to place an initial te.; sion therein. A series of springs 20 may be employed in side by side position, or a single long spring may be Wound spirally from one end to the other of the inner Wall 21.l 'After the placement of the springs 20, .fulcanizable rubber is then appliedV over the springs 2O cularly resilient reinforcing elements there- As herein set forth, it is profe 1able to make the internal diameter Il) of the protector 15 smaller than vthe external diameter of the pipe 11 on which it is to be mounted so that in placing the protector on the drill pipe it is necessary tostretch it and thus place the vulcanized rubber material of the inner and outer Walls v21 and 23 and the springs 20 vunder tension, this tension thereafter being exerted circularly so as to tend to produce a return of the drill pipe protector 15 to its original diameter, With the result that the pipe 11 is securely and forcibly gripped thereby. Although in the'preferred form of the invention I prefer to use a helically Wound spring 20, as shown in 4, other forms of springs may be employed in the circular, resilient reinforcement of the drill pipe protector 15. Illustrative of this, I have in Fig. 5 shown a ilat form of spring 30 Which may be satisfactorily employed in the practice of the invention. rlhe presence of the metal 'springs in the structure of the drill pipe protector produces a permanent resilience therein even though a portion of the resilience of the rubber employed should be lost due to the pounding action on the protector during its use in a well. Y

In a drill pipe protector such as shown, the rubber compound may be selected for its durability and non-frictional characteristics, and the necessary resilience for gripping a drill pipe may be produced therein by selecting spring reinforcing elements of proper strength, or a rubber compound of maximum strength and resilience may be selected and the total resilience of theprotector increased by use of spring reinforcing means of the character herein disclosed.

I claim as my invention:

1. A. drill pipe protector of the character described, comprising: a body of resilient, wear resisting material inA the form of a cylinder ha 'ing an opening to lit a drill pipe and an external diameter greater than the coupling means for joining such drill pipe; and circularly resilient reinforcement menbers within said body of resilient material.

2. A, drill pipe protector of the character described, comprising: a body of resilient, Wear resisting material in the form of a cylinder having an internal diameter smaller than the external diameter of a drill pipe structure on which said protector is to opera-te and an externalV diameter greater than the coupling means of such drill'pipe structure; 'and circularly resilient metallic reinforcement members within said body of resilient material.

8. A drill pipe protector of the character described, comprising: a body of resilient, Wear resisting material in the form of a cylinder having an internal diameter smaller than the external diameter of a drill pipe structure on Which said protector is to operate and an external diameter greater than the coupling means of such drill pipe structure; and circularly resilient metallic reinforcement members Within said body of resilient material, said resilient reinforcement members being under tension so as to produce atendency to circularly constrict saidresilient body and to cause same to forcibly grip said drill pipe structure.

4. A drill pipe protector of the character described, comprising: a cylindrical body of resilient, Wear resisting rubber compound having an internal diameter to fit a drill pipe structure on which said protector is to beV employed and having an external diameter greater than the coupling means of said drill pipe structure; and spring means extending circularly Within said cylindrical body.

5. A drill pipe protector of they character described, comprising: a cylindrical body of resilient, Wear resisting rubber compound having an internal diameter to fit a drill pipe structure on Which said protector is to be employed and having an external diameter greater than the coupling means of said drill pipe structure; and a plurality of circular metal springs placed side by side within said cylindrical body.

6. A drill pipe protector of the character described, comprising: a cylindrical body of resilient, Wear resisting rubber compound having an internal diameter to lit a drill pipe structure on Which said protector is to be employed and having an external diameter greater than the coupling means of said drill pipe structure; and spring means extending circularly Within said cylindrical body, said spring means having an initial tension therein for producing a circular constriction of said cylindrical body.

7. A drill pipe protector of the character described, comprising: a cylindrical body of resilient, Wear resisting rubber compound having an internal diameter to fit a drill pipe structure on Which said protector is to be employed and having an external diameter greater than the coupling means of said drill pipev structure; and a plurality of circular metal springs placed side by side Within said cylindrical body, said springs having an initial tension therein for producing a circular constriction of said cylindrical body.

is to be employed and having an external diameter greater than the coupling means of said drill pipe structure; and spring means 1xanding circularly within said cylindrical In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 21st day of January, 1930.

` WALTER G. L. SMITH.

8. A drill pipe protector of the character 

